Five Republican senators are fighting back against what they see as heavy-handed tactics by the Department of Justice to silence climate change skeptics.

Sen. Sheldon Whitehouse, D-R.I., may have shed light on the DOJ tactics at a Senate hearing in March when he pointedly told Attorney General Loretta Lynch, "Under President Obama, the Department of Justice has done nothing so far about the climate denial scheme."

Lynch replied, "We have received information about it and have referred it to the FBI."

Within days of that exchange, Democratic attorneys general from more than a dozen states fired off subpoenas seeking decades of records from climate change skeptics. Among them: university professors, scientists, corporations and think tanks including the Competitive Enterprise Institute.

"It's already had a chilling effect since we got the subpoena 45 days ago," said CEI's Sam Kazman. "This was a subpeona issued by the attorney general of the Virgin Islands for some reason."